The iceberg approaches for the Senate GOP’s ship, but unlike with the Titanic, there is plenty of time to turn. Republicans slowed the engines and thus the speed by postponing a vote until after the July 4 recess, but they are still set to collide with the consequences of breaking a core promise to the voters who sent them to Washington. If the GOP does not disengage the country’s health-care system from the disaster of Obamacare, we are headed for the misery of single-payer. This is the last chance to divert that outcome.

Sens. Ted Cruz (R-Tex.), Mike Lee (R-Utah), Ron Johnson (R-Wis.) and Rand Paul (R-Ky.) have their hands on the right side of the ship’s wheel. Sens. Shelley Moore Capito (R-W.Va.), Susan Collins (R-Maine), Cory Gardner (R-Colo.), Lisa Murkowski (R-Alaska) and Rob Portman (R-Ohio) have their hands on the left side of the wheel. Sen. Dean Heller (R-Nev.) is a man overboard and presumed lost in the D.C. seas. A miracle could still happen — Heller could figure out that jumping ship would doom his reelection and somehow climb back on board — but don’t count on it.

Not even trained psychiatrists could figure out the mixed motives of this gang of 10, but the policy realities are obvious. If the GOP fails to pass the Senate health-care bill, providers will continue to flee the Obamacare exchanges, leaving millions of Americans with no choices at all for buying health insurance. At least 18 counties in Ohio will likely be without any provider of individual plans in 2018. Tens of millions of Americans across the country will have a “choice” of one plan if they survive the death spiral of adverse selection. Premiums and deductibles, already spiraling up, will continue to soar.

The bill also makes needed changes to Medicaid. Devolving authority to the states will get the money into the local hands that know how to spend it. I’ve spent 18 years, concluding in March, on a local government commission charged in part with providing health services to the poor. We nine members of the Orange County Children and Families Commission knew — much better than state and especially federal bureaucrats — what our most stressed communities needed, and we built dental clinics, asthma programs, a center for autism and neurological disorders, and a vast newborn-care program. It may take a decade to complete Medicaid’s transition, but it must be done, because Medicaid as it exists is paper care that often does not even get you an appointment, much less care.

Beyond the policy reality, the political reality, as I wrote Monday, is especially stark for those opposing a compromise who also (rightly) want an “originalist” judiciary. Failure to pass a bill would doom more than the already self-immolated Heller. It would end the GOP’s House majority. It would take down Arizona Sen. Jeff Flake (an innocent bystander, as he will vote for the compromise) and probably lead to one upset loss in 2018 — perhaps Cruz, as disgusted Texas conservatives sit things out. Betraying a core promise — the core promise — to the GOP base would lose the Senate and thus the Supreme Court. Spare me the long-winded explanations: The “originalists” are forfeiting the court, for what?

Most of the senators avoided repeated invitations to appear on my radio show Monday or Tuesday to defend their intransigence, even those senators who are regular guests, likely because they know a no vote is indefensible. To his credit, Johnson appeared Monday but persuaded no one with his lame demands for more information on why premiums have soared. It’s a mystery what Johnson really wants, but everyone who has followed this debate knows the market forces at work, the “adverse selection” that is plaguing remaining insurers. What Johnson (and Paul and Collins) are going to get if they remain outliers, refusing to even debate the bill, is responsibility for everything wrong with their states’ health care beginning in 2018.

Some Republicans have a fantasy: The electorate will blame former president Barack Obama for the ongoing death spiral. Sorry, but that’s not how voters act. The power long sought by the GOP is in their grasp, and it turns out they are paralyzed. Indeed, many have lost their voices — their courage.

When the GOP won the House in 2010, the first thing we heard from John Boehner and his allies was that we control only half of one-third of the government.

When 2014 delivered the Senate, and thus the whole Congress, we heard that Obama’s veto could not be overridden.

Now there is a president who will sign their bill, if they can pass one. If they don’t, single-payer will arrive by default — the collapse of health care is not acceptable in a country as wealthy as ours — and the GOP will have earned a long exile. It’s a shameful capitulation to fear: fear of the media and fear of the Congressional Budget Office — even though the CBO’s health-care projections frequently have been wrong. The left and the right of the GOP caucus need to compromise now, or be marked as pushovers or worse. There is nothing they can say to defend this collapse.